Simple Vimeo embed example wrapping existing video iframe.

vimeo-embed-existing-iframe.js

/* Vimeo */
window.vimeo_players = [];
$('.video_container.vimeo').each( function () {
	$f($(this).find('iframe')[0]).addEvent( 'ready', (function ( player_id ) {
		if ( ! $(this).hasClass('no_thumbnail') ) {
			var thumbnail = $(this).find('.video_thumbnail'),
				play = $(this).find('.video_play'),
				player = $f( player_id );
			window.vimeo_players.push( player );
			var thumbnail_height = thumbnail.find('img').height();
			$(this).height(thumbnail_height);


			// Play button
			play.click( function () {
				player.api( 'play' );
				thumbnail.fadeTo( 200, 0, function () {
					thumbnail.css( 'z-index', 0 );
				});
			});
		}
	}).bind( this ));
});